1. Field of the Invention
The present invention relates to an exhaust system of a transverse V-type or horizontal opposed type engine.
2. Description of the Prior Art
In order to clarify the task of the present invention, one conventional exhaust system of a transverse V-type or horizontal opposed type engine will be outlined with reference to FIGS. 8 to 10 of the accompanying drawings.
As is seen from FIG. 8, the exhaust system comprises front and rear exhaust pipes (not shown) which are respectively provided for front and rear cylinder banks of the engine, front and rear catalytic converters (only rear catalytic converter 10 is shown) which are respectively connected to the front and rear exhaust pipes, a junction exhaust pipe 12 connected to the front and rear catalytic converters, and a combined exhaust pipe 14 which is connected to a muffler (not shown). The combined exhaust pipe 14 is arranged parallel to the rear catalytic converter 10 so that the exhaust gas flow in the rear catalytic converter 10 is in the opposite direction to that in the combined exhaust pipe 14.
As is seen from FIG. 9, the rear catalytic converter 10 has an elliptical section. The front catalytic converter also has an elliptical section. The major axis L.sub.1 of the elliptical section of the rear catalytic converter 10 is horizontally arranged, and thus directed toward the combined exhaust pipe 14. However, this conventional exhaust system has an increased exhaust loss and uneven utilization of a catalyst of the rear catalytic converter 10.
JP (Utility Model) 3-114522 A (1991) discloses an exhaust system of an internal combustion engine, which is substantially similar to the above-mentioned conventional exhaust system. That is, this publication also discloses a rear catalytic converter of which elliptical section has the horizontally arranged major axis.